/* Autonomous Systems Explained — refined technical publication styling */

:root{
  --max: 860px;               /* Ideal reading width for long-form articles */
  --maxWide: 1400px;          /* Wider layout for home / index pages */

  --fg: #111;
  --muted: #555;
  --bg: #ffffff;
  --panel: #fafafa;
  --line: #e8e8e8;

  --accent: #1f3b5c;          /* Deep technical blue (matches mark) */
  --accentSoft: rgba(31,59,92,0.08);

  --link: #0b57d0;
  --linkHover: #063a9a;

  --radius: 14px;
}

/* Base reset */
*{box-sizing:border-box}

html,body{
  margin:0;
  padding:0;
  font-family: system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.7;
  font-size: 18px;
  text-rendering: optimizeLegibility;
}

/* Layout containers */
.wrap{
  max-width: var(--max);
  margin: 0 auto;
  padding: 18px;
}

.wrap-wide{
  max-width: var(--maxWide);
  margin: 0 auto;
  padding: 18px 20px;   /* modest, standard padding */
}

/* Header */
header{
  border-bottom: 1px solid var(--line);
  background: var(--panel);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(6px);
}

/* Subtle accent line */
header::after{
  content:"";
  display:block;
  height:3px;
  background: linear-gradient(90deg, var(--accent), transparent);
}

/* Navigation */
nav{
  display:flex;
  flex-wrap:wrap;
  gap: 10px 14px;
  align-items:center;
}

nav a{
  color: var(--fg);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 10px;
  transition: background 0.15s ease;
}

nav a:hover{
  background: var(--accentSoft);
}

/* Brand */
.brand{
  display:flex;
  align-items:center;
  gap:10px;
  text-decoration:none;
  color:var(--fg);
}

.brand img{display:block}

.brand-text{
  font-weight:600;
  white-space:nowrap;
}

/* Headings */
h1{
  margin: 10px 0 12px;
  font-size: 36px;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

h2{
  margin: 30px 0 12px;
  font-size: 22px;
  letter-spacing: -0.01em;
  line-height: 1.25;
}

h3{
  margin: 24px 0 8px;
  font-size: 18px;
  line-height: 1.3;
}

/* Text */
p{margin: 12px 0}
small,.muted{color: var(--muted)}

/* Links */
a{color: var(--link)}
a:hover{color: var(--linkHover)}
a:focus{
  outline: 3px solid rgba(11,87,208,0.25);
  outline-offset: 2px;
  border-radius: 8px;
}

/* Cards */
.card{
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  margin: 18px 0;
  background: #fff;
  position: relative;
}

/* Subtle top accent bar */
.card::before{
  content:"";
  position:absolute;
  left:0;
  top:0;
  width:100%;
  height:4px;
  border-radius: var(--radius) var(--radius) 0 0;
  background: var(--accentSoft);
}

/* Lists */
ul{
  padding-left: 20px;
  margin: 12px 0;
}

li{margin: 6px 0}

/* Code */
code{
  background: #f2f2f2;
  padding: 2px 6px;
  border-radius: 8px;
  font-size: 0.95em;
}

pre{
  background: #f6f6f6;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  overflow:auto;
  font-size: 0.95em;
}

/* Article meta badge */
.article-meta{
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.95em;
  display:inline-block;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
}

/* Notes */
.note{
  border-left: 4px solid var(--accent);
  padding: 12px 16px;
  background: #fcfcfc;
  border-radius: 10px;
  margin: 18px 0;
}

/* Table of contents */
.toc{
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  background: #fff;
  margin: 20px 0;
}

.toc a{text-decoration:none}
.toc a:hover{text-decoration:underline}

/* Ads */
.ad-block{
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
  background: #fafafa;
}

/* Author box */
.author-box{
  margin-top: 30px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

/* Footer */
footer{
  border-top: 1px solid var(--line);
  background: var(--panel);
  margin-top: 30px;
}

/* Wide screens */
@media (min-width: 1200px){
  :root{ --max: 920px; }
}

/* Mobile adjustments */
@media (max-width: 720px){
  .brand-text{display:none;}
}

@media (max-width: 520px){
  html,body{font-size: 17px}
  h1{font-size: 28px}
  .wrap,.wrap-wide{padding: 14px 14px}
}

.content-narrow{
  width: 100%;
  max-width: 940px;
  margin: 0 auto;
  padding: 0; /* prevent double-padding when inside wrap-wide */
}

/* Normal page text width on wide layouts (home/about/index pages) */
.wrap-wide > h1,
.wrap-wide > p,
.wrap-wide > ul,
.wrap-wide > .ad-block,
.wrap-wide > .card{
  max-width: 1400px;
  margin-left: auto;
  margin-right: auto;
}